Field
This document relates to a patterned retarder type stereoscopic image display device capable of reducing 3D crosstalk and a method for driving the same.
Related Art
Stereoscopic image displays are classified into displays using a stereoscopic technique and displays using an autostereoscopic technique. The stereoscopic technique uses parallax images of left and right eyes to implement enhanced 3D effect. The stereoscopic technique includes a glasses method and a non-glasses method, both of which have been put to practical use. The glasses method may be classified into a patterned retarder method and a shutter glasses method. In the patterned retarder method, polarization directions of left and right parallax images are changed to display the left and right parallax images on a display device and implement a 3D image using polarization glasses. In the shutter glasses method, left and right parallax images are displayed on a display device in a time-division manner to implement a 3D image using liquid crystal shutter glasses. In the non-glasses method, optical parts, such as a parallax barrier and a lenticular lens, are used to separate optical axes of left and right parallax images and implement a 3D image.
FIG. 1 is a view showing a patterned retarder type stereoscopic image display device. Referring to FIG. 1, the patterned retarder type stereoscopic image display device implements a stereoscopic image by using polarization characteristics of a patterned retarder PR disposed on a display panel DIS and polarization characteristics of polarization glasses PG worn by a user. The patterned retarder type stereoscopic image display displays a left-eye image on odd-numbered lines of the display panel DIS and displays a right-eye image on even-numbered lines of the display panel DIS. In the patterned retarder PR, first retarders RET1 are formed on the odd-numbered lines, and second retarders RET2 are formed on the even-numbered lines. The left-eye image of the display panel DIS is converted into first circularly polarized light by the first retarders RET1, and the right-eye image of the display panel DIS is converted into second circularly polarized light by the second retarders RET2. A left-eye polarization filter of the polarization glasses PG allows only the first circularly polarized light to pass therethrough, and a right-eye polarization filter thereof allows only the second circularly polarized light to pass therethrough. Thus, the user views only the left eye image through his or her left eye and views only the right eye image through his/her right eye.
FIG. 2 is a table illustrating luminance values of left-eye image data and right-eye image data supplied to the related art stereoscopic image display device. Referring to FIG. 2, the present applicant supplied left-eye image data RGBL having a 255 gray scale value G255 and right-eye image data having a 255 gray scale value G255, a 191 gray scale value G191, a 127 gray scale value G127, a 63 gray scale value G63, and a 0 gray scale value G0, and then measured the luminance of a left-eye image input into the left-eye filter of the polarization glasses PG.
Because the left-eye filter of the polarization glasses PG allows only the left-eye image to pass therethrough, the luminance of the left-eye image having passed through the left-eye filter of the polarization glasses PG has to be uniform irrespective of the right-eye image. However, as shown in FIG. 2, the luminance of the left-eye image having passed through the left-eye polarization filter of the polarization glasses PG increases as the gray scale value of the right-eye image data RGBR increases. In other words, the luminance of the left-eye image having passed through the left eye polarization filter of the polarization glasses PG is affected by the luminance of the right-eye image. Hence, the related art patterned retarder type stereoscopic image display device may experience a three-dimensional (3D) crosstalk, in which the user sees doubled images by leaking part of the left-eye image into the right-eye image and vice versa. The 3D crosstalk may cause user inconvenience when the user views the stereoscopic image.